Pull through sharpeners...what you wish they'd told you.

It is almost inconceivable that some knife manufacturers still sell or recommend pull-through sharpeners. They may be quick and convenient, but they are one of the worst ways to maintain a good kitchen knife.

Most pull-through devices force every knife through the same fixed angle, regardless of its original edge geometry. Coarse tungsten-carbide models can scrape away excessive amounts of steel, leaving a rough, weakened edge. Finer ceramic versions have the opposite problem: they may refresh a relatively new edge, but often cannot remove enough metal to properly sharpen an older, thicker blade.

Every time a knife is sharpened, its edge moves slightly closer to the spine, where the blade is thicker. Eventually, merely polishing the very edge is not enough. Steel must be removed behind the edge to restore the knife’s correct geometry. Pull-through devices cannot properly thin the blade, so the knife gradually becomes thick and blunt behind the edge—more like the edge of a spoon than an efficient cutting tool.

We regularly receive knives scarred by pull-through sharpeners. Common damage includes:

• Deep scratches along the knife extending above the bevel that cannot be removed. ( below )

• Excessively thick edges where extra thinning is needed.
• Shredded and lacerated steel along the cutting edge ( see image below from our workshops)

Pull-through sharpeners sell because they appear simple and produce an immediate result on a relatively new knife—not because they provide good long-term care. Of all the commonly available knife-sharpening devices, they are among the very worst.

Our advice is simple: steer clear of pull-through sharpeners. Use an appropriate honing rod for light maintenance, learn to use a whetstone correctly, or have your knives professionally sharpened before their geometry becomes compromised.